1. Field of the Invention
The present invention relates to a contact lens capable of simultaneously correcting myopia and suppressing the progression of myopia.
2. Description of the Prior Art
Regarding a conventional contact lens, the correction power is provided by the central zone of the lens only. The peripheral zone of the lens does not provide correction power and is designed such that the contact lens has a shape conforming to the shape of the eyeball and can be worn easily. FIG. 1 is a schematic representation illustrating the image formation of a conventional contact lens 110. After a parallel light beam has passed through the conventional contact lens 110, the central zone of the conventional contact lens 110 forms a central-zone focus 01 right on the retina while the peripheral zone of the conventional contact lens 110 forms a peripheral-zone focus 02 behind the retina because the peripheral zone of the conventional contact lens 110 does not provide correction power. Current researches show that the growth of the eyeball can be effectively suppressed to slow the progression of myopia if the peripheral-zone focus 02 image is formed in the front of the retina by a myopic defocus effect. FIG. 2 is a schematic representation illustrating the image formation of a conventional contact lens 210 for myopia control. After a parallel light beam has passed through the conventional contact lens 210 for myopia control, a central-zone focus 01 is formed on the retina while a peripheral-zone focus 02 is formed in front of the retina to achieve the effect of myopia control. However, as the focuses of the two zones are distantly formed, the wearer may feel uncomfortable and be less tempted to wear such contact lenses.